Heat exchanger



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. HEAT EXCHANGER Filed March 15, 1955 iUL .................. NHHHH Y H-.. -h--- NV EN To R s BERN/IP13 FR/EDMAN Fem/m 0 5. H0255 United States Patent [Ce HEAT EXCHA-N GER Bernard Friedman, Roseland, and Fernando E. Flores, Newark, N. J., assignors to Tenney Engineering, Inc., Union, N; 1., a corporation of New Jersey ApplicationMarch 15', 1955, Serial No. 494,322 3 Claims. (Cl. 257-247) This invention relates to heat transfer devices and more specifically to an improved heat exchanger or condenser that can be readily coupled to provide two hermetically sealed circuits and wherein two or more like units may be readily coupled in various ways (as in series or in parallel) to meet the requirements of a specific application.

One object of the invention resides in the provision of an improved heat exchanger characterized by high efiiciency, low cost and versatility. By reason of the particular design and arrangement of the elements of this exchanger it can be used to interconnect two hermetically sealed systems and will function effectively to condense gases at very low temperatures without unduly loading the condensing medium.

Still another object of the invention resides in the provision of a heat exchanger having at least two individual hermetically sealed conduits wherein free drainage of the condensed liquid is attained. When used in refrigeration systems, this exchanger enables maximum utilization of the condensed liquid with the result that the quantity of refrigerant in the system may be reduced.

A still further object of the invention resides in the provision of a new and improved heat exchanger wherein ratio of surface to volume may be modified .to attain optimum fluid velocity, volume and pressure drops.

The above and other objects and advantages will become more apparent from the following description and accompanying drawings forming part of this application.

In the drawings:

Fig. 1 is a side elevational view of one embodiment of a heat exchanger in accordance with the invention; and

Fig. 2 is an end view of the heat exchanger shown in Fig. 1.

The heat exchanger in accordance with the invention is made up of elements comprising an outer tube of relatively large diameter having its ends pinched or deformed so as to provide, in effect, upper and lower openings. In other words, the tube ends are formed substantially to figure eight section. An inner tube is disposed diagonally within the outer tube between the upper opening at one end and the lower opening at the other end. The remaining openings are utilized for the attachment of connections for the formation of a second fluid path. By suitably welding or soldering the ends of the outer tube about the inner tube and connections for the outer tube, two separate hermetically sealed fluid conduits are provided that are ideally suited for the transfer of heat one to the other.

More specifically and with reference to the drawings, the heat exchanger comprises a series of substantially identical sections or elements 10, 1 1, 12, etc. with each section having an outer tube 14 preferably of cylindrical section and an inner tube 24. The end portions 16 and 18 of each outer tube are pinched or deformed as may be observed in Fig. 2 to form in the illustrated embodiment upper and lower circular openings 20 and 22, respectively.

Patented se t.24, 1957 downwardly from left to right in section 10, from right to left in section 1 1 and so on. The illustrative assembly is completed by uniting adjacent ends of the inner tubes by means of return bends 28 and coupling the outer tubes by means of connections 26 seated in the remaining upper and lower openings 20 and 22. By welding all joints and connections, two separate hermetically sealed fluid paths are thus provided. It will be understood that the designations upper and lower as applied to the openings 20 and 22 are for convenience in describing this particular arrangement and that two or more assemblies 10, 11, etc. can be variously connected to meet the needs of a particular installation.

In the assembly illustrated, the path formed by the inner tubes has suflicient slope to provide free drainage that is particularly important in the condensation of gases. In addition the outer fluid or liquid path formed between the walls of the inner and outer tubes causes the medium flowing therein to pass across the inner pipe or tube 24 to produce more effective heat transfer. While the tubes in the illustrated embodiment of the invention are of circular section they may of course be made with any desirable configuration.

In the use of this invention in refrigeration systems, for instance, the free drainage of the condensed medium when flowing through the inner tubes 24 enables maximum utilization of the refrigerant so that the quantity of fluid in the system can be retained at a minimum. Then, too, when using the device at low temperatures, the exterior surface of tubes 14 will provide a heat transfer surface that will dissipate heat from the cooling medium and thereby enable it more effectively to remove heat from the load being condensed.

Because of the rugged and dependable structure of this heat exchanger it is also particularly useful in high pressure refrigeration systems and allows a minimum volume to be handled with maximum transfer of heat thus vastly improving the efliciency of the system. The simplicity and versatility of the invention effects substantial economy in manufacture and enables a designer to select inner and outer tube combinations that will provide any desired ratio of surface to volume to attain an optimum velocity, volume and pressure drop that may be required for a specific application.

While only one embodiment of the invention has been shown and described, alterations, changes'and modifications may be made without departing from the true scope and spirit thereof.

The following is claimed:

1. In a heat exchanger, upper and lower horizontally disposed outer tubes, each said tube having both of its ends pinched to form upper and lower openings, an inner tube diagonally disposed in the upper tube between the upper opening at one end of such tube and the lower opening at the other end, an oppositely diagonally disposed inner tube in the lower outer tube between the upper opening at one end of such tube and the lower opening at the other end and a connection between the lower end of the'first-mentioned inner tube and the unoer end of the second-mentioned inner tube.

2. In a heat exchanger, upper and lower horizontally disposed outer tubes, each said tube having both of its ends pinched to form upper and lower openings, an inner tube diagonally disposed in the upper tube between the upper opening at one end of such tube and the lower opening at the other end, an oppositely diagonally disposed inner tube in the lower outer tube between the upper opening at one end of such tube and the lower opening at the other end, a connection between the lower end of the first-mentioned inner tube and the upper end of the second-mentioned inner tube, and a connection between the remaining lower opening of the upper outer tube and the remaining upper opening of the lower outer tube.

3. In a heat exchanger, the combination of upper and lower open-ended outer tubes, each tube having both of its ends deformed to provide upper and lower openings with a restricted neck between them, an inner tube of lesser diameter extending diagonally within the upper outer tube with its ends disposed and sealed, respectively,

4 in an upper and lower one of said openings, a like inner tube extending oppositely diagonally within the lower outer tube with its ends disposed and sealed, respectively, in an upper and lower one of said openings, a U-shapecl coupling element having sealed connection at its ends with the lower end of the upper inner tube and the adjacent upper end of the lower inner tube and a U-shaped coupling element having sealed connection at its ends with the remaining lower opening of the upper outer tube 10 and therernaining upper opening of the lower outer tube.

References Cited in the file of this patent UNITED STATES PATENTS Persichetti Dec. 17, 1918 2,305,992 Quillen Dec. 22, 1942 

